Production of EPA and DHA in aquatic ecosystems and their transfer to the land.
Level 5 - mechanism / opinion, no new human data
Narrative review of ecological mechanisms and food-web dynamics without new human data or systematic review methodology.
PubMed 23500063 · doi:10.1016/j.prostaglandins.2013.03.002
What was done
This narrative review synthesized ecological and biochemical literature on the de novo production of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by aquatic microalgae and their trophic transfer across food webs into terrestrial ecosystems and human diets.
What was found
Microalgae are identified as the primary de novo synthesizers of EPA and DHA. These essential polyunsaturated fatty acids transfer through trophic chains with approximately twice the efficiency of bulk carbon, accumulating in higher trophic organisms such as fish. Transfer to terrestrial ecosystems occurs via riparian predation, carrion and seaweed drift, emergent amphibiotic insects, and water birds. While alternative sources like aquaculture and biotechnology are developing, natural aquatic production remains a vital global source. No further numerical metrics are reported in the abstract.
Why it matters
It highlights that terrestrial animals and humans fundamentally rely on aquatic primary producers for critical omega-3 fatty acids. This underscores how anthropogenic stressors on aquatic ecosystems—such as warming, pollution, and eutrophication—directly threaten the global nutritional supply of EPA and DHA.
Limits
The paper is a qualitative narrative review rather than a systematic review or meta-analysis. The abstract provides broad ecological concepts without quantitative effect sizes, confidence intervals, sample sizes, or formal dietary intake assessments.
Cited by
- supports Fish do not synthesize EPA and DHA de novo in meaningful quantities, but obtain them by consuming microalgae at the base of the marine food chain.